This is a series of powerful and macabre photos from 1865 showing the hanging execution of the four Lincoln conspirators: Mary Surratt, Lewis Payne, David Herold, and George Atzerodt. They were condemned to death for their involvement in the assassination of President Abraham Lincoln and were hanged on Friday, July 7th, 1865.
Conspirators standing on the scaffold

Here the four are standing on the scaffold, hoods being placed over their heads, and nooses over their necks. They only have moments left to live.
Close up of the scene

And here’s a close up of the scene, which is fascinating. They are about to hang Mary Surratt, the first white woman to be executed by the United States government, but they are kind enough to shade her with a parasol from the hot Washington summer sun.
Reading the death warrant

Above, the death warrant for the four is being read aloud by General John F. Hartranft. They only have moments left on this Earth.
Reading the death warrant

This is a close-up of the reading of the death warrant. More parasols are out now providing shade from the sun.
Nooses being adjusted

Now the nooses were being adjusted around the necks of the guilty.
The face of George Atzerodt

This is where the close-up view is really powerful. You can see the the face of George Atzerodt clearly on the right. It’s hard to imagine what is going through his mind at the moment this photograph was taken.
Hanging hooded bodies

The next photo shows the scene after the four were hanged. They’re all dead and hanging motionless while the crowd is beginning to disperse.
Young boy looks at gallows

Click on the above image for a larger version. What really caught my attention in this image is what you see below. A young boy is standing near some soldiers, just staring at the four lifeless bodies. What’s going through his mind? He just witnessed the execution of four conspirators found guilty of assassinating the President of the United States.
Scaffold in use and crowd

Here is an alternate view of the scene from outside the fort.
Coffins and open graves

Finally, here is a photo of the scaffold with coffins and graves dug next to it.
Source: Library of Congress